Bat sonar and wing morphology predict species vertical niche

Area of Science:

• Ecology
• Bioacoustics
• Evolutionary Biology

Background:

• Insectivorous bats use echolocation for navigation and foraging in darkness.
• Interspecific competition may drive co-evolution of sonar features, wing morphology, and vertical distribution.

Purpose of the Study:

• To empirically demonstrate the correlation between bat acoustic features, wing morphology, and vertical distribution.
• To investigate how bats partition vertical space to minimize competition.

Main Methods:

• Deployed microphone arrays on 48 wind masts to record bat echolocation calls.
• Monitored the vertical distribution of 19 bat species and 2 species groups over an annual activity period (>8000 nights).
• Correlated flight height proportions with acoustic call features and wing morphology parameters.

Main Results:

• Bat call peak frequency and bandwidth significantly predict vertical space utilization.
• Wing aspect ratio and wing loading are associated with a higher proportion of time spent at higher altitudes.
• These findings hold true irrespective of the bats' acoustic foraging strategies (gleaning, hawking, prey flutter detection).

Conclusions:

• Acoustic properties and wing morphology are key adaptations for vertical niche partitioning in bats.
• Empirical evidence supports the hypothesis that sonar and flight characteristics co-evolved with vertical distribution to reduce competition.